(1) Technical Field
The present invention relates to a buoyant force control apparatus for scuba diving, in particular, to buoyant force control apparatus for scuba diving having a simple construction without an oral inflator hose and a valve box, so that even beginners can manipulate without erroneous operations and safety of the apparatus is additionally increased.
(2) Prior Art
According to the conventional buoyant force control apparatus for scuba diving, they are classified to that, for example, of a jacket type, a life jacket (hang-on-neck) type which are worn on a diver's suit of the diver, and of a shoulder-belt type attached to the diver's wear.
For example, FIG. 4 depicts an example of the jacket type vest and a conventional buoyant force control apparatus applied to the vest of the diver.
In detail, according to the prior art above, the vest 32 has an inner air chamber 31 and has an oral inflator hose 33 consisting of a large diameter flexible hose of about 50 mm dia. The upper opening port of the oral inflator hose 33 is communicated with the inner air chamber 31 at a position of the shoulder of a half part of a front portion of the vest 32. The lower opening port of the oral inflator hose 33 is connected to the valve box 34 through connection of the hose 33 and an end of a main tube 35 of the valve box 34 as shown in FIG. 5. To the valve box 34, a mouth piece 36 for sending or supplying air to the air chamber 31 is secured so as to communicate with the main tube 35. A valve rod 38 for closing and opening the tube portion or passage 37 communicating with the mouth piece 36 from the main tube 35 is inserted into the main tube. The valve rod 38 has a button 39 for supplying and exhausting air fixed thereto. A lower opening port of a middle-pressure hose 41 connected to an air tank or reservoir 40 through an upper end of the hose 41 are connected to an air supply tube portion or passage 42 leading to the main tube 35.
It is apparent that an air supply button 44 is provided at an outer end of a valve rod 43 for closing and opening the air supply tube passage 42. At the position of other shoulder of another half part of the vest front portion, there is an overpressure prevention valve 45 which is led to the air chamber 31. A pull string 46 for releasing the overpressure prevention valve 45 is inserted through a guide tube 47 secured to the front face portion of the vest 32 so as to be suspended along the front face portion and has a grip ball 48 fixed to a depending end of the pull string 46 so as to make pulling of the pull string easy.
When the diver wearing the conventional buoyant force control apparatus wants to control buoyant force as he is under water or on the water and to supply air to the air chamber 31 of the vest 32, first he pushes the air supply button 44 to release the closed condition of the air supply tube passage 42 by means of the valve rod 43 in order to make the air supply tube passage 42 led to the main tube passage 35. As a result, a predetermined volume of air in the air tank 40 is supplied to the air chamber 31 of the vest 32 through the air supply tube passage 42 of the valve box 34, a main tube passage 35 and the oral inflator hose 33, and then a pressed condition of the air supply button 44 is released and the air supply tube passage 42 is closed by the valve rod 43 returned to its original position so as to shut a communication between the air supply tube passage 42 and the main tube passage 35 stopping air supply. Air leak is prevented or the air supply and exhaust button 39 is pushed in order to release a closed condition of the mouth piece tube passage 37 using the valve rod 38, the mouth piece tube passage is led to the main tube passage 35. A mouth of the driver is applied to the mouth piece 36 and air is blown to supply a predetermined volume of air to the air chamber 31 through the main tube passage 35 and the oral inflator hose 33. Then the pressed condition of the air supply and exhaust button 39 is released and the valve 38 closes the mouth piece tube passage 37 in order to shut down it from the main tube passage 35, stopping air supply, as well as preventing air leak.
On the contrary, in order to exhaust air from the air chamber 31, first the valve box 34 is held in a hand of the driver or the user as shown in FIG. 5, the hand is raised high and kept at its high position, the air supply and exhaust button 39 is pressed to release the closed condition of the mouth piece tube passage 37 leading it to the main tube passage 35 and the predetermined volume of air is escaped or exhausted through the mouth piece 36. Then, a pressed condition of the air supply and exhaust button 39 is released, the valve rod 38 closes the mouth piece tube passage 37 to shut down it from the main tube passage 35 in order to stop further flowing-out of air-through the mouth piece tube passage 37. Alternately, the pull string 46 for releasing the tube passage of the overpressure prevention valve 45 is pulled to exhaust the predetermined volume of air and the pull string 46 is set free to close the tube passage stopping additional air flowing.
However, according to the conventional buoyant force control apparatus for scuba diving, the driver or user must carry out the air supply and exhaust operation or button pushing and releasing manipulation by only his fingers while the hand holds the valve box 34 and rises high as shown in FIG. 5, so that in particular beginners of the conventional buoyant force control apparatus or inexperienced diver using the apparatus apt to do erroneous operations or manipulations dangerously. Only the upper opening or port of the oral inflator hose 33 is fixed to an upper portion of the vest 32 and the lower portion of the oral inflator hose 33 is not attached to the vest 32 since the driver must rise the valve box 34 high and operates it at this raised condition, so that the oral inflator hose 33 with the valve box 34 is apt to move to the back of the vest 32 while the user swims or moves under water. In consequence, when he wants to use the valve box 34 in an emergency, he frequently cannot find or touch the valve box 34. Additionally a long hose or complicated hose system is installed on the diver's vest hindering him from free movement and a large bag is need to store the diving applicance. These above have been problems or risks to be solved in the field.